Character frequency in a text

charFreq.cpp

// Example program

#include <iostream>
#include <string>
#include <map>
#include <cstddef>

int main()
{
    std::string text = "Mr Trump, who has flown to Florida for the Thanksgiving holiday on Thursday, is still assembling his White House team. One of America's top generals, David Petraeus, has told the BBC he would be willing to serve under him.";
    std::map<char, std::size_t> freq;
    for(auto c: text)
    {
        if( freq.find(c) == freq.end())
            freq[c] = 1; 
        else
            ++freq[c];
    }

    int i=0;
    for(auto elem: freq)
    {
        std::cout << i++ <<". "<< elem.first << " -> " << elem.second << std::endl;
    }
}